BIOSYNTHESIS OF PHENOLS .20. SYNTHESIS OF ANTHRAQUINONES THROUGH CARBANIONS OF ORTHO-SUBSTITUTED BENZOPHENONES

Treatment of 2-cyanomethyl-2′,4′-dimethoxybenzophenone with sodium methoxide in dimethyl sulphoxide gave 9-cyano-2-methoxyanthracen-10-ol in 95% yield. This was oxidised to 2-methoxyanthraquinone in almost quantitative yield, under mild conditions. The relevance of this synthesis of anthraquinones to possible pathways of biosynthesis has been discussed. The interaction of 2-cyanomethyl-2′,4′-dimethoxybenzophenone and sodium methoxide in methanol gave 3-methoxy-1-(2,4-dimethoxyphenyl)isoquinoline.